Apparatus for washing impurities from gas



April 2 8, 1942. A. w. ANTHONY, JR

APPARATUS FOR WASHING IMPURITIES FROM GAS Filed Sept. 17, 1940 PatentedApr. 28, 1942 APPARATUS FOR WASHING IMPURITIES FROM GAS Waltham, Mass.,assignor Alfred W. Anthony, Jr., to Pease, Anthony E quipment Company,Cambridge, Mass, a corporation of Massachusetts Application September17, 1940, Serial No. 357,105

3 Claims.

The present invention is concerned with improvements in the type ofapparatus disclosed in the prior patent to Pease No. 1,992,762, datedFebruary 26, 1935.

It is the purpose of this general type of apparatus as disclosed in thePease patent to promote an intimate gas and liquid contact for thepurposes of removing impurities, solid or otherwise, present in the gas,and providing extended surface for chemical or mechanical interaction.This is accomplished mainly by imparting a whirling or spinning velocityto the gas as it rises in the treating chamber, and delivering into therising body of gas centrally thereof a finely divided liquid spray whichis caused to partake of the spinning velocity of the gas and workoutwardly to the boundary of the treating zone. The delivery of thisliquid to the gas body generally takes place at the lower portion of thetreating zone, and I have found that there may be some tendency,particularly when a reduced volume of gas is delivered to the chamber,for a certain percentage of the finely divided liquid droplets to carryupwardly along the axis of the delivery zone and thence outwardlywithout making intimate contact with the surrounding spinning gas body.

I have discovered that through the provision of a diverting surfacelocated in the central or delivery portion of the treating zone andabove the region of liquid delivery, I can divert the rising column offinely divided liquid sufiiciently to cause the liquid droplets topartake of the spinning velocity of the surrounding gas body, which thenengenders suflicient the droplets outwardly to the edge of the zone,where the liquid droplets strike the surrounding wall of the zone.

For the accomplishment of my discovery I have found that a generallyconical diverting surface of a diameter not greater than half thediameter of the treating chamber and located centrally thereof, willsatisfactorily divert a col umn of droplets suificiently to cause anoutward spinning or traverse through centrifugal force to the outerboundaries of the gas body.

In-the accompanying drawing illustrating the p'fiferred form of myinvention, Fig. 1 represents a section in elevation of a scrubbing towerembodying my invention; Fig. 2 is a section on the line 22 of Fig. 1;and Figs. 3 and 4 are sectional views illustrating slight modificationsof the diverting surfaces.

The illustrated embodiment of the invention is shown in connection witha scrubbing tower or energy to spin the like of the general naturedisclosed in the Pease patent above referred to. Such a scrubbing towerhas a circular casing l0, elongated in the direction of its axis andupright in its working position. The gas to be treated is admittedthrough a conduit l2, having a tangential admission I 4 adjacent thelower end of the treating chamber, and serving to admit gas in such amanner as to cause a generally whirling or revolving motion of the gasbody which progresses upwardly and finally emerges through the centraloutlet I6, as indicated somewhat by arrows in Fig. 1. The scrubbingliquid is admitted through a pipe 28, which connects with a centrallydisposed spray column 20, having a series of spray nozzles 22 whichserve to deliver substantially along the axis a great quantity of finelydivided droplets. It may be stated that the division of this spray is sofine that it is not possible under ordinary conditions to precipitatethe spray by virtue of its initial momentum completely across the gasbody to the wall of the treating chamber. However, the spray in itsfinely divided condition is picked up and entrained in the revolving gasbody, and through centrifugal force thereby engendered works outwardly,causing a complete and intimate contact with the gas body, and finallyengaging with the wall of the chamber.

In this type of structure, and depending upon the volume. of gas treatedwith relation to the size of the treating chamber, there may be a smallvolume of spray-laden gas which clusters about the axis, and which doesnot traverse the gas body to accomplish its intended function. Thissmall volume of spray under normal conditions works upwardly, remainingin the center of the chamber where the spinning velocity of the gas isso low as not to engender any substantial centrifugal force in theliquid, finally emerging through the outlet in the form of entrainment.

This objection I obviate in a very simple manner, by providing a disk 30located axially of the treating chamber and having a diameterapproximately one-third to one-half of the diameter of the treatingchamber. This disk may be supported at intervals by brackets 32,extending from the wall of the treating chamber and/or by a centrallydisposed post 34, as indicated in Fig. 1. The under surface of the diskdiverts this rising column of liquid spray outwardly to a point wherethe spinning velocity of the gas body will create sufficient centrifugalforce upon the spray particles themselves to work them outwardly to thewall of the treating chamber. In

actual practice, I find that there is a concentration of wetness in theform of a ring on the wall of the treating chamber about and slightlyabove the surface of the disk when the diverting surface is employed,showing that such spray as would otherwise pass upwardly through theoutlet at low gas loadings, is diverted and precipitated on the wall ofthe chamber and eventually passes down and outwardly through the waste40.

In Figs. 3 and 4 I have shown a slightly modifled form of such adiverting surface, in both cases the diverting surface, instead of beingthat of a flat disk, is an outwardly flaring cone 50, supported in thesame manner as previously described, and serving to divert axiallymoving liquid particles. The structure shown in Fig. 4 differs from thatin Fig. 3, as the diverting surface 50 may be surmounted by a similarbut reversed conical surface 52 to close the space within the divertingsurface. In either case the surface functions in much the same manner asthe flat disk-like surface to divert these flne particles of liquidoutwardly to zones of higher tangential velocity, which spin them to thewall of the chamber.

In this connection it is understood and must be appreciated that theprime function of the diverting surface is in connection with a treatingchamber where the delivery of the liquid particles to the surroundinggas body is of such a character that they cannot normally with theinitial velocity imparted thereto traverse the entire body of gas, butmust rely upon the spinning velocity of the surrounding gas body to pickup and impart suiiicient momentum for the desired traverse to the wallof the chamber.

What is claimed is:

1. Apparatus for gas-liquid contact, comprising an elongated treatingchamber, means for imparting a spinning velocity to the body of gaswithin the chamber, means for delivering centrally of the spinning gasbody a spray of liquid divided into droplets preponderantly so fine asto be incapable of traversing the gas body through their initialmomentum, and means for interposing centrally of the chamber above thedelivery of the liquid spray a diverting surface of a diameter of aboutone-third to one-half the diameter of the chamber in a position todivert outwardly an axially rising cloud of droplets which otherwisewould pass through the outlet without traversing the gas body, thechamber being substantially unobstructed in the space surrounding saidsurface.

2. Apparatus for gas-liquid contact, comprising an elongated treatingchamber of generally circular cross-section, means for introducing gastangentially of the chamber at one end thereof, axially located meansfor introducing a spray of finely divided droplets into the centralportion of the gas body, the numerical preponderance of the dropletsbeing incapable through their initial momentum to traverse the gas bodyto the margin of the treating zone, and a divertting disk locatedaxially of the treating chamber and beyond the liquid spray, the surfaceof the disk being adapted to divert that portion of the spray confinedto the axis of the treating chamber outwardly to a point at whichcentrifugal force acts upon and causes the spray to traverse the gasbody to the margin thereof, the chamber being substantially unobstructedin the space surrounding said disk.

3. Apparatus for gas-liquid contact, comprising an elongated treatingchamber of generally circular cross-sections, means for admitting gas atone end of the chamber, means for removing treated gas from the oppositeend of the chamber and centrally thereof, means for delivering aplurality of sprays of liquid axially of the chamber and near the end atwhich the gas is introduced, and a diverting disk of about onethird toone-half the diameter. of the chamber located axially of the chamber andinterposed between the spray device and outlet, to outwardly divert thefinely divided liquid to the zones of higher rotational velocities ofthe gas, the chamber being substantially unobstructed in the spacesurrounding said disk.

ALFRED W. ANTHONY, JR.

